<select name="category_id" class="form-control">
	<option value="">请选择分类</option>
	{volist name="$category_tree" id="v"}
	{if $data['category_id'] == $v['id']}
	<option value="{$v['id']}" selected><b>{$v['title']}</b></option>
	{else}
	<option value="{$v['id']}"><b>{$v['title']}</b></option>
	{/if}
	{if !empty($v['_child'])}
		{volist name="$v['_child']" id="_v"}
		{if $data['category_id'] == $_v['id']}
		<option value="{$_v['id']}" selected>|----{$_v['title']}</option>
		{else}
		<option value="{$_v['id']}">|----{$_v['title']}</option>
		{/if}
		{/volist}
	{/if}
	{/volist}
</select>
<div class="help-block">请选择分类</div>